Reaction of 1-nitroso-2-naphthol (I) with isopropylamine in water gives 2-isopropylamino-1-nitrosonaphthalene (II). After hydrogenation, condensation of the resulting 2-isopropylamino-1,2-naphthalendiamine (III) with p-methoxybenzaldehyde yields the 1,2-dihydro derivative (IV), which is converted to MDL-035 with palladium on carbon. Toluene is used as a solvent throughout the synthesis. The overall yield on a 20-kg scale is 57%.